Computers, even though they use efficient integrated circuits, can require substantial amounts of power. This electrical power is provided by specially designed power supplies. These power supplies, especially those used with large computers, create substantial amounts of heat which must be dissipated. This is often done by blowing air past the circuit boards of the power supply.
To aid the repair of a power supply with a defective component, the various components are often mounted to a number of circuit boards which are individually removable from the power supply housing. One way this is done is by slidably mounting the circuit boards in rows within the power supply housing. During removal and replacement of the circuit boards from and into the housing, the boards can be guided along their upper and lower edges by tabs or other guide elements extending from the upper and lower surfaces of the housing. The circuit boards preferably have contacts at their outer edges which engage complementary contacts of an electrical connector mounted within the housing.
Certain computers are made with redundant components. Therefore if one or more components on one circuit board fail, that circuit board can be removed while the computer, and thus the power supply, continues to operate. One of the problems with such a continuously operational computer is that the power supply often has very high voltages present at the connectors to which the removed circuit board had previously been engaged. The high voltages create a safety hazard to a technician working to repair the power supply. To help prevent the technician from injury, protective partitions or panels have been mounted in the power supply housing adjacent the printed circuit boards. The panels extend to positions near the connectors to which the circuit boards connect. These panels, which remain within the housing when the board is removed for servicing, help to prevent accidental injury to the technician by partially blocking inadvertent contact with the adjacent circuit boards, which are still energized, during servicing. The panels also help to guide cooling air blown through the housing to help insure proper cooling of the circuit board components.
The guide elements used previously were typically formed by deforming the top and bottom surfaces of the housing. This was done by partially punching out short sections of the housing and bending them to create short circuit board and partition guide elements. This method was somewhat limiting in that later rearrangement or repositioning of the circuit boards could only be done by reworking the housing or building a new housing. The partially punched out and bent members limit how close the circuit boards and panels could be mounted to one another. Also, the punched out openings allow cooling air to escape through the housing which lowers the cooling efficiency of the system.
Another type of guide elements used to support side-by-side slidably mounted protective panels and circuit boards, is a plastic card guide. These commercially available card guides are elongate strips mounted to the upper and lower surfaces of the housing with a central groove formed therein. The edges of the circuit boards are housed within the slots to support and guide the circuit boards. These guide elements, however, restrict how close one can mount the partitions to the circuit boards which can reduce the packing density below that desired. They are also time consuming to install.